From patchwork Wed May 11 08:35:52 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Russell King - ARM Linux X-Patchwork-Id: 776912 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p4BGKZRY014043 for ; Wed, 11 May 2011 16:20:35 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757465Ab1EKQUN (ORCPT ); Wed, 11 May 2011 12:20:13 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:57714 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757432Ab1EKQUK (ORCPT ); Wed, 11 May 2011 12:20:10 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=arm.linux.org.uk; s=caramon; h=Sender:In-Reply-To:Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date; bh=Bd0Gkc6IDEsu8Y8+kxJxNv1+wIGMevlsnWPny2yYK14=; b=Yd75CaNg8jguyN/F5kfgOFQiiBjrI+YdWwqVJ3SYGR6NuCmkYrAirDY9nlD6ViiQPT1XwORb3WAWZiStULuey4leDvze3tD0AKqd2yhN0SeV+qR9oez6Pl4/u6DHoHYk4gYvHO4IkITxHwwqtxsRAho/1GJZFcPat73V+K2tnJs=; Received: from n2100.arm.linux.org.uk ([2002:4e20:1eda:1:214:fdff:fe10:4f86]) by caramon.arm.linux.org.uk with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.72) (envelope-from ) id 1QK4te-0006if-E3; Wed, 11 May 2011 09:35:55 +0100 Received: from linux by n2100.arm.linux.org.uk with local (Exim 4.72) (envelope-from ) id 1QK4tc-00047z-Uh; Wed, 11 May 2011 09:35:52 +0100 Date: Wed, 11 May 2011 09:35:52 +0100 From: Russell King - ARM Linux To: linux-arm-kernel@lists.infradead.org, John Stultz , Thomas Gleixner Cc: Kukjin Kim , Eric Miao , Linus Walleij , Erik Gilling , Nicolas Pitre , Tony Lindgren , Krzysztof Halasa , linux-omap@vger.kernel.org, "Hans J. Koch" , Sascha Hauer , Colin Cross , Olof Johansson , Imre Kaloz , Wan ZongShun , Lennert Buytenhek , Alessandro Rubini Subject: [PATCH 06/13 v2] clocksource: add common mmio clocksource Message-ID: <20110511083552.GF15120@n2100.arm.linux.org.uk> References: <20110510072700.GA29869@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Wed, 11 May 2011 16:20:36 +0000 (UTC) Add a generic mmio clocksource, covering both 32-bit and 16-bit register access sizes, for up or down counters. This can be used to easily create clocksources for simple counter-based implementations. Cc: Alessandro Rubini Cc: Colin Cross Cc: Eric Miao Cc: Erik Gilling Acked-by: "Hans J. Koch" Cc: Imre Kaloz Cc: Krzysztof Halasa Cc: Kukjin Kim Cc: Lennert Buytenhek Cc: Linus Walleij Cc: linux-omap@vger.kernel.org Cc: Nicolas Pitre Cc: Olof Johansson Tested-by: Sascha Hauer Cc: Tony Lindgren Reviewed-by: Viresh Kumar Cc: Wan ZongShun Signed-off-by: Russell King --- This is the version with cs->reg initialized. drivers/Kconfig | 3 ++ drivers/clocksource/Kconfig | 2 + drivers/clocksource/Makefile | 1 + drivers/clocksource/mmio.c | 73 ++++++++++++++++++++++++++++++++++++++++++ include/linux/clocksource.h | 8 ++++ 5 files changed, 87 insertions(+), 0 deletions(-) create mode 100644 drivers/clocksource/Kconfig create mode 100644 drivers/clocksource/mmio.c diff --git a/drivers/Kconfig b/drivers/Kconfig index 177c7d1..557a469 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -119,4 +119,7 @@ source "drivers/platform/Kconfig" source "drivers/clk/Kconfig" source "drivers/hwspinlock/Kconfig" + +source "drivers/clocksource/Kconfig" + endmenu diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig new file mode 100644 index 0000000..47f37b1 --- /dev/null +++ b/drivers/clocksource/Kconfig @@ -0,0 +1,2 @@ +config CLKSRC_MMIO + bool diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index be61ece..9b2ba29 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -6,3 +6,4 @@ obj-$(CONFIG_CS5535_CLOCK_EVENT_SRC) += cs5535-clockevt.o obj-$(CONFIG_SH_TIMER_CMT) += sh_cmt.o obj-$(CONFIG_SH_TIMER_MTU2) += sh_mtu2.o obj-$(CONFIG_SH_TIMER_TMU) += sh_tmu.o +obj-$(CONFIG_CLKSRC_MMIO) += mmio.o diff --git a/drivers/clocksource/mmio.c b/drivers/clocksource/mmio.c new file mode 100644 index 0000000..c0e2512 --- /dev/null +++ b/drivers/clocksource/mmio.c @@ -0,0 +1,73 @@ +/* + * Generic MMIO clocksource support + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include +#include +#include +#include + +struct clocksource_mmio { + void __iomem *reg; + struct clocksource clksrc; +}; + +static inline struct clocksource_mmio *to_mmio_clksrc(struct clocksource *c) +{ + return container_of(c, struct clocksource_mmio, clksrc); +} + +cycle_t clocksource_mmio_readl_up(struct clocksource *c) +{ + return readl_relaxed(to_mmio_clksrc(c)->reg); +} + +cycle_t clocksource_mmio_readl_down(struct clocksource *c) +{ + return ~readl_relaxed(to_mmio_clksrc(c)->reg); +} + +cycle_t clocksource_mmio_readw_up(struct clocksource *c) +{ + return readw_relaxed(to_mmio_clksrc(c)->reg); +} + +cycle_t clocksource_mmio_readw_down(struct clocksource *c) +{ + return ~(unsigned)readw_relaxed(to_mmio_clksrc(c)->reg); +} + +/** + * clocksource_mmio_init - Initialize a simple mmio based clocksource + * @base: Virtual address of the clock readout register + * @name: Name of the clocksource + * @hz: Frequency of the clocksource in Hz + * @rating: Rating of the clocksource + * @bits: Number of valid bits + * @read: One of clocksource_mmio_read*() above + */ +int __init clocksource_mmio_init(void __iomem *base, const char *name, + unsigned long hz, int rating, unsigned bits, + cycle_t (*read)(struct clocksource *)) +{ + struct clocksource_mmio *cs; + + if (bits > 32 || bits < 16) + return -EINVAL; + + cs = kzalloc(sizeof(struct clocksource_mmio), GFP_KERNEL); + if (!cs) + return -ENOMEM; + + cs->reg = base; + cs->clksrc.name = name; + cs->clksrc.rating = rating; + cs->clksrc.read = read; + cs->clksrc.mask = CLOCKSOURCE_MASK(bits); + cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS; + + return clocksource_register_hz(&cs->clksrc, hz); +} diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 94c1f38..a3558fd 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -341,4 +341,12 @@ static inline void update_vsyscall_tz(void) extern void timekeeping_notify(struct clocksource *clock); +extern cycle_t clocksource_mmio_readl_up(struct clocksource *); +extern cycle_t clocksource_mmio_readl_down(struct clocksource *); +extern cycle_t clocksource_mmio_readw_up(struct clocksource *); +extern cycle_t clocksource_mmio_readw_down(struct clocksource *); + +extern int clocksource_mmio_init(void __iomem *, const char *, + unsigned long, int, unsigned, cycle_t (*)(struct clocksource *)); + #endif /* _LINUX_CLOCKSOURCE_H */